This chapter explores the nationalist ideology of the Rizospastai of the Ionian Islands, an exceptional group of political activists who dominated the Septinsular political arena from the 1840s until the end of British Protection in 1864. It explores how the party was formed and how it developed, before focusing on the radical concept of nationalism as expounded by its chief theoreticians. In terms of primary material, the chapter relies on the official administrative papers of the British Protectorate, housed in the national archives. The contrast is between political groupings based on ideology and a specific political agenda, and parties formed around sources of power, such as a charismatic individual or an influential foreign state. The dawn of that turbulent century had seen the establishment of the short-lived Septinsular Republic, the first nominally independent Greek state since the fall of Constantinople.